Ask Mr Brain...all will be explained
Why are old-fashioned diseases like tuberculosis and malaria coming back? Bacteria have a secret weapon - mutation - which makes them resistant to a specific antibiotic. Therefore, doctors often prescribe more than one drug to treat an infection.
The body's natural immune system also helps out, but new strains of germs still emerge.
At present there is a drug-resistant tuberculosis epidemic. It is particularly a problem in urban, poverty-stricken areas and among people whose immune systems have been weakened by Aids.
Although tuberculosis spreads through the air, experts say we are unlikely to get it from, for example, riding on a bus. The big threat is to health-care workers who come into contact with a lot of patients. But there is no easy solution to the long- term problem.
Why do some drinking fountains shoot water from two holes instead of one? The two-hole water fountain is made by Halsey-Taylor, one of the giants of the industry. The design causes the two streams of water to converge at the apex of the arc of water and supposedly creates a better drink.
More importantly, the two streams aerate the water as it rises towards your mouth, and aerated water does not taste as stale.
What does the Jurassic Period mean? The Jurassic Period is the second of the three geological periods that constitute the Mesozoic Era, spanning the interval of time from 208 to 144 million years ago.
It follows the Triassic and pre cedes the Cretaceous Period. In the Jurassic Period, reptiles attained their maximum size and were found on land and in the sea and air. The shallow Jurassic seas were rich in marine life - ammonities and clams proliferated. On land the flora included ferns and conifers. Small rat-sized mammals and the first birds were also found.
Why did Michael Jordan average less than 18 points a game at university? Michael Jordan, the world's greatest basketball player, averaged only 17.7 points a game during his three years at the University of North Carolina.
Not once did he score 40 points in a single game. The reason was that his coach Dean Smith concentrated on teamwork without depending on one man to win a game.
North Carolina was a much better team with Jordan passing the ball, playing defence and, of course, shooting, says an expert.
Subsequently, Jordan averaged well over 30 points a game with the NBA's Chicago Bulls on his way to becoming an American icon.